Quantum phases of Fermi-Fermi mixtures in optical lattices

Abstract

The ground state phase diagram of Fermi-Fermi mixtures in optical lattices is analyzed as a function of interaction strength, population imbalance, filling fraction and tunneling parameters. It is shown that population imbalanced Fermi-Fermi mixtures reduce to strongly interacting Bose-Fermi mixtures in the molecular limit, in sharp contrast to homogeneous or harmonically trapped systems where the resulting Bose-Fermi mixture is weakly interacting. Furthermore, insulating phases are found in optical lattices of Fermi-Fermi mixtures in addition to the standard phase-separated or coexisting superfluid/excess fermion phases found in homogeneous systems. The insulating states can be a molecular Bose-Mott insulator (BMI), a Fermi-Pauli insulator (FPI), a phase-separated BMI/FPI mixture or a Bose-Fermi checkerboard (BFC).

12 pages with 6 figures. Extended version of arXiv:cond-mat/0612496

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Cited by in corpus (7)

• Population imbalanced fermions in harmonically trapped optical lattices
• Cooper pairing, flat-band superconductivity and quantum geometry in the pyrochlore-Hubbard model
• Attractive Hofstadter-Hubbard model with imbalanced chemical and vector potentials
• Spatially-modulated Superfluid States in Fermionic Optical Ladder Systems with Repulsive Interactions
• Hofstadter-Hubbard model with opposite magnetic fields: Bardeen-Cooper-Schrieffer pairing and superfluidity in the nearly flat butterfly bands
• Correlated Phases of Population Imbalanced Fermi-Fermi Mixtures on an Optical Lattice
• Anomalous dispersion of the collective modes of an ultracold ${}^{6}Li-$ ${}^{40}K$ mixture in a square optical lattice